Hello,

Introduction

     These are short programs that implement a "state machine".
These are similar to the state machine described in the August
1986 "Scientific American" magazine.  In this state machine,
a pixel's state in the next cycle depends on the states of the
four neighboring pixels in this cycle.  These programs are meant
to be run in video mode 6.

File Description

README   TXT             This file
MODE6    COM        10   switches to video mode 6 for PSEUDO3
PSEUDO2  COM       622   Starts with a block fill for "carpet patterns"
PSEUDO3  COM       613   Starts with current screen
TEST2    BAT        70   Example for PSEUDO3 with dot
TEST3    BAT        74   Example for PSEUDO3 with text
PSEUDO4  COM       634   Starts with center two pixels on "diamonds"

Usage

     PSEUDO2 and PSEUDO4 are stand alone programs.  PSEUDO3 needs
an external setup to provide mode 6 and something on the screen.
It can actually use mode 4 or 5, but things are a little different
there and is not what was intended.  The *.BAT files are starters
for someone to play with.

     MODE6.COM switches video modes if you need to for PSEUDO3.
PSEUDO3 is intended to allow you to set up a different beginning
pattern to see the resulting patterns.  As this program dosen't
clear the screen or change video modes, you must ensure that you
are in mode 4, 5, or 6.  The idea is to set the video mode, clear
the screen, put something on the screen to seed the state machine,
and then run PSEUDO3.

Comments

     Stefan Peichl's Carpet Designer was the start of this silly-
ness.  He posted an amazingly small graphics program to the HPLX
list.  I thought I could take an old program I wrote for my Z-100
and translate it to use CGA graphics and be small enough to squeak
by the no binaries limit.  Say about 250 - 300 bytes.  Well after
the usual dull thuds, I brute forced a working program.  Oops, too
big now.  But I e-mailed the program to a couple of people.  Stefan
Peichl suggested sending these to S.U.P.E.R and including the source.
Well I went through the source and declared the work area and fixed
a bug or two.  These are functionally the same as the older versions,
but are larger because of the work area.  The source contains comment
errors, and because of the "tiny" program effort, is not a good exam-
ple of assembly code for beginners.

     Another state machine is "Life" or "The Game of Life" created by
John Conway.  Many implementations exist for all sorts of displays.

     This program runs nicely on the HP 200LX letting you see the
state machine cycle from one screen to the next.  On faster machines
you get a significantly different "animated" effect and can't see a
lot of the details in action.

     Enjoy.

     Steve

Other Comments

     Stefan Peichl noted that,

"using a compression tool like COMPACK (from s.u.p.e.r.) brings
your COMs down to about 600 bytes!"
